Methods for the production of computer-tomographic scans by way of a CT system during an intervention on a patient with an instrument are generally known.
An intervention with the aid of a medical instrument with CT observation in this case relates to a metallic needle which is used, for example, to carry out a nerve blockade or to treat a tumor, with this needle being inserted into the body in a known manner parallel to the scanning X-ray beams, or the gantry being pivoted with its rotation plane on which the X-ray tube and the opposite detector are located to such an extent that the X-ray beams run parallel to the instrument, and reconstructed images are then made available to the operator, with these images being arranged in the immediate vicinity of and parallel to the instrument. An image is generally displayed which shows a longitudinal section through the intervention instrument in order to provide the operator with as good an overview as possible of the area directly surrounding the intervention instrument. The intervention direction is in this case generally oriented at right angles to the system axis or longitudinal axis of the patient.
It has been found that artifacts which lead to an unsatisfactory image display are produced during computer-tomographic scans such as these.